Fix node.js segfault on pogoplug e02

Customized CXXFLAGS(`-march=armv5t`) for arm was not effective in the package function.
And then, re-compiled with enabled `-march=armv5te` by `make install`
(`CXXFLAGS` of default's makepkg.conf was included `-march=armv5te` on pogoplug e02)

Therefore, set flags in package function.